In recent years, efforts for decreasing an energy consumption amount are emphasized. In view of such a background, Light Emitting Diodes (LEDs) that have a relatively little power consumption are getting attention as a next-generation light source. LEDs are compact, have a little amount of heat generation, and have an excellent responsiveness. Hence, LEDs are widely applied in various optical devices. For example, in recent years, a module that has a right source which is LEDs arranged on a flexible and light transmissive substrate has been proposed.
Lights from LEDs are monochromatic color lights, such as Red (R), Green (G), and Blue (B). Hence, in order to accomplish a white light and an intermediate-color light using a light source that includes LEDs, it is necessary to use multiple LEDs that emit different color lights.